Researchers at Carnegie Mellon University have used nuclear resonance vibrational spectroscopy to probe the hydrogen bonds that modulate the chemical reactivity of enzymes, catalysts and biomimetic complexes. The technique could lead to the development of better catalysts for use in a wide range of fields. The findings were published as a "Very Important Paper" in the Dec. 3 issue of Angewandte Chemie and featured on the journal's back cover.
Hydrogen bonds are among the most fundamental interactions found in biology and chemistry. They are responsible for many of the chemically important properties of water, for the stabilizing the structures of proteins and nucleic acids, including those found in DNA and RNA, and contribute to the structure of natural and synthetic polymers.
Research has shown that hydrogen bonds play an important role in tuning the reactivity of the metal centers of metalloenzymes and metal containing catalysts.
However, little research has been done to experimentally demonstrate how systematic changes to hydrogen bonds within the secondary coordination sphere -- molecules found in the vicinity of metal centers that do not have direct bonding interactions with the center -- influence catalytic activity.
In catalysis, enzymes or synthetic catalysts spur on a chain of chemical reactions, which produce a number of intermediate structures or species. Understanding those structures and their chemical properties is key to understanding the entire reaction.
"Thoroughly understanding the chemical reactivity of the reactive intermediate is a key step to determining how to design highly efficient and selective catalysts for C-H functionalization," said Yisong Guo, assistant professor of chemistry at Carnegie Mellon and the study's lead author.
"In the case of dioxygen-activating enzymes, the key intermediates of catalysis are iron-oxo (Fe-O) and iron-hydroxo (Fe-OH) species, which are involved in important biological processes, such as DNA biosynthesis, DNA and RNA repair, post-translational modification of proteins, biosynthesis of antibiotics and degradation of toxic compounds."
Guo and colleagues used 57Fe nuclear resonance vibrational spectroscopy (NRVS), a newly developed synchrotron radiation-based technique, to detect the vibrational frequency of Fe-O and Fe-OH units of synthetic complexes that interact with the secondary coordination sphere through hydrogen bonds.
Changes in the frequencies revealed valuable information about the bond strengths of these units and further provided a qualitative measure of hydrogen bond strength.
"This showed that NRVS is a sensitive technique to pick up very small changes in hydrogen bond strength, down to the changes of a single hydrogen bond.
This provides us with a new method to connect changes in bond strength of Fe-O and Fe-OH units to their chemical reactivity," said Guo.
Guo says that this study is a proof-of-concept for using NRVS to probe hydrogen bonds. He plans to continue using this method to study more iron-oxo and iron-hydroxo species in both synthetic complexes and enzymes to build up the amount of available data to correlate chemical reactivity of these species with the changes of hydrogen bond interactions, with the hope that that information could be used to develop more efficient and effective catalysts.
All of the experimental data in this study was recorded at the Advanced Photon Source at Argonne National Laboratory, which is supported by the Department of Energy. Computation was completed using the Extreme Science and Engineering Discovery Environment (XSEDE) and Bridges System at the Pittsburgh Supercomputing Center, which is funded by the National Science Foundation (NSF). The research was funded by the National Institutes of Health (GM050781, GM077387) and NSF (1654060).
Study authors include Guo, Andrew C. Weitz, Emile M. Bominaar and Michael P. Hendrich from the Carnegie Mellon University and Andrew S. Borovik, Ethan A. Hill and Victoria F. Oswald from the University of California, Irvine.
Jocelyn Duffy | EurekAlert!
Another piece of Ebola virus puzzle identified
17.01.2019 | Texas Biomedical Research Institute
New scale for electronegativity rewrites the chemistry textbook
17.01.2019 | Chalmers University of Technology
World first experiments on sensor that may revolutionise everything from medical devices to unmanned vehicles
The new sensor - capable of detecting vibrations of living cells - may revolutionise everything from medical devices to unmanned vehicles.
Dead and alive at the same time? Researchers at the Max Planck Institute of Quantum Optics have implemented Erwin Schrödinger’s paradoxical gedanken experiment employing an entangled atom-light state.
In 1935 Erwin Schrödinger formulated a thought experiment designed to capture the paradoxical nature of quantum physics. The crucial element of this gedanken...
Cellulose obtained from wood has amazing material properties. Empa researchers are now equipping the biodegradable material with additional functionalities to produce implants for cartilage diseases using 3D printing.
It all starts with an ear. Empa researcher Michael Hausmann removes the object shaped like a human ear from the 3D printer and explains:
The phenomenon of so-called superlubricity is known, but so far the explanation at the atomic level has been missing: for example, how does extremely low friction occur in bearings? Researchers from the Fraunhofer Institutes IWM and IWS jointly deciphered a universal mechanism of superlubricity for certain diamond-like carbon layers in combination with organic lubricants. Based on this knowledge, it is now possible to formulate design rules for supra lubricating layer-lubricant combinations. The results are presented in an article in Nature Communications, volume 10.
One of the most important prerequisites for sustainable and environmentally friendly mobility is minimizing friction. Research and industry have been dedicated...
Just in time for Christmas, a Mars-analogue mission in Morocco, coordinated by the Robotics Innovation Center of the German Research Center for Artificial Intelligence (DFKI) as part of the SRC project FACILITATORS, has been successfully completed. SRC, the Strategic Research Cluster on Space Robotics Technologies, is a program of the European Union to support research and development in space technologies. From mid-November to mid-December 2018, a team of more than 30 scientists from 11 countries tested technologies for future exploration of Mars and Moon in the desert of the Maghreb state.
Close to the border with Algeria, the Erfoud region in Morocco – known to tourists for its impressive sand dunes – offered ideal conditions for the four-week...
16.01.2019 | Event News
14.01.2019 | Event News
12.12.2018 | Event News
17.01.2019 | Physics and Astronomy
17.01.2019 | Materials Sciences
17.01.2019 | Information Technology